FLOW STRING HOLDER Russian patent published in 2009 - IPC E21B33/14 

FIELD: oil and gas industry.

SUBSTANCE: flow string holder refers to oil and gas industry and can be implemented at casing of wells, at executing operations in earlier bored wells when boring second borehole, and also for holding liner in borehole of well under bearing plate of producer. The holder consists of a bore connected with upper and lower subs and of a case forming a circular cavity, wherein a piston resting on a cone is installed. Also the cone is made with angle from 4° to 12° to axis of the holder; a telescopic collet is arranged under the cone; the collet is made from flexible brackets and screw-thread dies with teeth. A stop with slots is rigidly mounted on the lower sub; the flexible brackets of the collet enter these slots upon actuation of the holder. The invention increases reliability of flow string holder operation due to the fact, that the cone transforming axial force into radial one affects screw-thread dies of the telescopic collet, which rests in place in preliminary meshing with an internal wall of the column. Depth of penetration of teeth of the screw-thread die of the collet into metal of cased pipes increases in direct proportion to axial effort from weight of the column.

EFFECT: increased reliability of flow string holder operation due to fact, that cone transforming axial force into radial one affects screw-thread dies of telescopic collet, which rests in place in preliminary meshing with internal wall of column.

2 dwg